Low Heart Ratr

Im trying not to stress but I went to the ER yesterday so that I could find out how far along i truly was (my old obgyn told me 15 weeks) Im only 6 weeks (needless to say he's been fired). Doc told me baby heart rate was extremely low at a 57per min when it should be 100. Someone tell me some good news, how I could help my baby heart rate to increase, or amything!! I tried google and it was depressing.